1. Field of the Invention
This invention relates to a novel organic compound and more particularly it relates to an alkenyl ether compound useful as a liquid crystal component and a liquid crystal composition containing the same.
2. Description of the Related Art
Liquid crystals have recently been becoming more and more important as a dielectric for liquid crystal display devices and the reason consists in an electrooptical effect based on the dielectric anisotropy and the optical anisotropy of liquid crystalline substances. Liquid crystal display modes based on liquid crystals include dynamic scattering mode, phase transition mode, DAP mode, guest-host mode, TN mode using a 90.degree. twist cell, STN or SBE mode using a 180.degree.-270.degree. twist cell, etc. It is necessary for liquid crystals used for liquid crystal displays to satisfy a number of necessary characteristics such as a broad mesomorphic range, a good stability to environmental factors (e.g. moisture, heat, air, light, electricity, etc.), colorless, values of physical properties suitable to display modes used, etc. For example, in the case of a SBE mode, a characteristic required therefor consists in that the voltage-transmittance characteristic (.gamma. characteristic) is steep. As a parameter expressing the steepness of the .gamma. characteristic, there are elastic constant ratios K.sub.33 /K.sub.11 and K.sub.33 /K.sub.22, and when the values of the elastic constant ratios K.sub.33 /K.sub.11 and K.sub.33 /K.sub.22 are high, the .gamma. characteristic becomes steep (Nakagome et al, the 12th Liquid Crystal Symposium, 3-F13 (1987)).
Herein, K.sub.11 refers to an elastic constant of splay, K.sub.22 refers to an elastic constant of twist and K.sub.33 refers to an elastic constant of bend.
At present, there is no single compound satisfying all of these necessary characteristics; hence actually, there have been used liquid crystal mixtures obtained by mixing several kinds of liquid crystal compounds or by mixing compounds having latent liquid crystallinity or non-crystalline compounds with several kinds of liquid crystal compounds. Thus, it is also required that liquid crystals have a good, compatibility with other liquid crystal compounds.